Drive means for continuous mining machine



March 1, 1960 c. B. KREKELER 2,926,896

DRIVE MEANS `FOR CONTINUOUS MINING MACHINE Filed Dec. 50, 1958 BYMvM,

ATTORNE YS.

`points or ends of the bits tent Office 2,926,896 Patented Mar. 1 196@zpzasss DRIVE MEANS FOR `CNTIIJUOUS MINING MACHINE Claude B. Krckeler,Monfort Heihts, Ohio, assignor to The Cincinnati Mine Machinery Co.,Cincinnati,` Ghia, a corporation of Ohio Application December 3i), 1958,Serial No. 783,957 8 Claims. (Cl. 262-29) This invention relates to minemachinery and more particularly to a continuous mining machine for usein cutting into veins of coal or the like.

In continuous mining machines provision is made for supporting andfeeding a plurality of clo'sed chains formed of pivoted-together blockswhich mount and support bit holders and cutter bits in such a way thatthe cutting enter into cutting relation with the mineral vein.

to pass around sets of sprockets secured to a pair of shafts, one of theshafts being journaled at the extreme forward end of the machine so thatthe cutter bits make cutting contact with the mineral vein as they passaround the sprockets on the forward shaft, the upper flights of thechains moving'rearwardly where they pass around the second shaft whichis arranged to be driven from any suitable source of power, such as aprime mover connected to the shaft through gearreduction means. Withthis arrangement, the upper llights of the cutter chains also serve as amoving conveyor effective to move the coal or other mineral matterfromthe cutting area so that it may be collected for removal from the mine,as by means of belt conveyors, coal cars and the like.

The instant invention is directed specifically tov improvements in themanner in which the sprockets are mounted to the forward shaft aboutwhich the cutter chains move as `they cut into the mineral vein.Heretofore these forward shafts have been formed by taking a singlepiece of :rod stock and milling away its outermost ends to provide 'aVcentral section having a first diameter and outermost our end sectionshaving a second and reduced diameter. In a conventional construction thecentral` portion of the shaft is arranged to mount three u sprockets inspaced apart relation, the sprockets being splinedV to the shaft, withan additional sprocket splined to the reduced section at each end of theshaft. In addition, pineapples or rotary cutters are tted over the endsof the end sections of the shaft and splined thereto. The shaft isjournaled in suitable bearings mounted on the machine frame, thebearings being so arranged that the shoulders between the center sectionof the shaft and the reduced `end sections will abut against the bearingmembers `to prevent axial displacementof the shaft.

With the arrangement just described, considerable difficulty h asrbeenexperienced Vin accurately aligning the splines in the center section ofthe shaft with those in Vthe `reduced end sections. That is, by reasonof the change in diameter between the central and end sections,

Y itis extremely dicult to set the cutting tool to produce preciselongitudinal alignment betveen the splined portions of the threesections. Since, in the conventional assembly, all of the frontsprockets are driven in unison from the rear shaft, even the slightestmisalignment of any one of the front shaft splines produces an unequalload on the cutter chains. This unequal load not only adversely affectsthe smooth operation of the cutter but subjects the front shaft toexcessive wear and Vinternal The `cutter chains are arranged twistingmovement resulting in either distortion or breakage of the shaft as wellas mutilation of the splines.

it is a principal object of the instant invention to overcome thedifficulties just noted by providing a construction wherein accuratealignment between the splines on the center and outer parts of the shaftis not required, the two outside sprockets, i.e. the sprockets mountedon the end sections of the shaft, being designed to float on the shaft,thereby reducing the load on the outside chains.

A further object of the invention is the provision of a shaft andsprocket arrangement of the character noted `wherein the front shaft isadapted to be driven solely by the intermediate sprockets, i.e. thesprockets secured to the center section of the shaft, and wherein theoutside sprockets mounted on the reduced ends of the shaft are rotatablyVreceived on splined inserts which permit the outside sprockets `to seektheir own alignment relative to the shaft and the intermediatesprockets. As before the pineapples onthe ends of the shaft are splineddirectly to the reduced end portions thereof, and hence will be drivenby the shaft as it is rotated by means of the intermediate chains andsprockets.

Still a further object of the invention is the provision sprockets inplace of the double tooth sprockets heretofore employed in devices ofcomparable size, the single tooth sprockets serving to permit bettertracking of the cutter chains and reducing the tendency of the chains totwist. Preferably, five tooth sprockets will be ernployed in replacementof the four double tooth sprockets heretofore used. This change has beenfound to reduce joint wear, thereby increasing the life of the joints.At the same time, a fewer number of double bit blocks are required andyet the total number of bits is the same as with the longerpitched'chains.

The foregoing objects of the invention together with others which willappearhereinafter or which will be apparent to the skilled worker in theart upon reading the specification, I accomplish by that constructionand arrangement of parts of which l' shall now describe an exemplaryembodiment. Y

Reference is now made to the accompanying drawings wherein:

Figure l is a plan View with parts broken away of the cutting end of acontinuous mining machine. f

Figure 2 is a vertical sectional View taken along the line 2`-2 ofFigure l with the parts at one .side of the machine shown inexplodedrelation.

Figure 3 is an elevational view of a sprocket mounting shaft formed inaccordance with the invention Y Figure 4 is a schematic View intended toillustrate the mode of operation of the cutting device.

For a general understanding of the invention, reference is first made toFigure 4`of the drawings wherein the front or leading shaft is indicatedby the reference numeral i, the shaft having an enlarged center section2 and reduced end sections 3. it` will be understood that the termsenlarged and reduced are terms of convenience and have been chosen todenote a .center section having a larger diameter than the end sections.

ln the embodiment illustrated a series of three inter mediate sprockets4 are splined to the enlarged center section ofthe shaft and outermostsprockets 5 are adapted to be journaled on the end sections 3. While inthe drav ings (Figure 4), the sprockets E. are showndetached from theshaft 1, this is simply to illustrate that the sprockets 5 are drivenindependently of the shaft even though they areiournaled on it. Therotary cutters or pineapples 6 are, however, splined to the endsectiousof the shaft and are rotated thereby.

The cutter chain assemblies 7 which pass around the sprockets 4 alsopass around coacting sprockets 3 assess@ mounted on splined shaft 9adapted to be driven through gear box 1f) from any suitable prime mover(not shown). Outermost sprockets 11 are also splined to the rear shaft10 and connected by cutter chain assemblies 12 to the sprockets 5. Itwill be understood that all of the sprockets on rear shaft 9 will bedriven in unison by the rear shaft. However, as previously indicated, byreason of the varia- Vtion in diameter between the center and endsections of the forward shaft-which is necessary to provide shoulders toprevent axial displacement of the forward shaftprecise alignment betweenthe splines in the center and end sections of the forward shaft cannotbe readily obtained, and any misalignmeut of the splines results inmisalignment of the sprockets 4 and 5 relative to each other and unequalloading between the intermediate cutter chain assemblies 7 and theoutermost cutter chain assemblies 12.

As best seen in Figures l and 2, each of the cutter chain assembliescomprises a plurality `of double cheek chain elements 13 having mountingblocks 14 in which one or more cutter bits 15 are secured. The doublecheek elements 13 are connected together by means of intermediate singlecheek elements 16, the elements being pivoted together by suitablepiutles 17, as will be readily understood, thereby forming an endlesscutter chain. While in the embodiment illustrated each of the cutter bitmounting blocks mounts a pair of cutter bits extending in oppositedirections, it will be understood that the arrangement may be variedwith the bits in staggered relation. For example, single cutter bits maybe mounted on given blocks with the bits in either vertical position orinclined to one side or the other. Thus, in a typical chain assembly,adjacent pairs of blocks mounting double cutter bits may be followedconsecutively by blocks mounting single bits extending left, right, andleft, whereupon, the sequence is repeated.

As also seen in Figures 1 and 2, the front and rear shafts are journaledin suitable bearings, such as the bearings 13 for the shaft 1 and thebearings 19 for shaft 9, the bearings being.V mounted to a machine framewhich includes longitudinally extending rib members 20 to whichelongated plates 21 are secured, the plates lying between the chainassemblies in the manner illustrated. Side guides or sweeps 22 arepreferably mounted on the outermost frame members to channel thematerial cut from the vein rearwardly of the machine. As will beapparent in Figure 2, the bearings are so arranged that they will abutagainst the enlarged center section 2 of the shaft, thereby preventingaxial displacement of the shaft. While the enlarged center section 2 maybe formed as an integral unit, i.e. of a length to mount all of theintermediate sprockets 4, it mayV also be divided into a plurality ofspaced apart sections 2a (see Figure 3) with the intermediate portions23 of the shaft machined to a lesser diameter, as for example the samediameter as the end sections 3. Where this is done, intermediate bearingmembers 18a (Figure 2) may be provided between the spaced apart enlargedcenter sections.

The outermost sprockets are fitted on the end portions of the shaft 1 bymeans of splined inserts 24 which are received on the splined outer ends3 of the shaft. The center openings or bores 25 of the sprockets 5 areof a size to be fited over the inserts 24, in the manner seen in theleft-hand portion of Figure 2. Preferably the titting will be a snug onealthough it will be such that relative aligning movement may be effectedbetween the insert and the sprocket.

The center bores 26 of the rotary cutters or pineapples 6 are alsosplined and are fitted directly on the ends of the shaft and secured inplace by means of clamping plates 27 and threaded nuts 2S. Thepineapples are thus driven directly by the shaft 1 which in turn isdriven by the intermediate cutter chains. While some driving force maybe transferred to the shaft through the outermost sprockets 5, thesesprockets are essentially independent of the shaft insofar as thedriving forces are concerned. That is, the outermost sprockets are freeto seek their own alignment and, while they will be driven insynchronism with the intermediate sprockets, they are not relied upon topower the shaft but rather to convey the outermost chain assemblies.

It has been found that the arrangement just described has solved aserious production problem in the machining of the sprocket mountingshafts and, at the same time, has increased the life of such shafts byeliminating the torque or twist which resulted from improperly alignedsprockets. The construction also reduces the load on the outermostchains and at the same time increases their wearing ability. It alsopermits the use of single tooth sprockets which are more desirable inthat the cutter chains track better and vibration is reduced.

Having thus described the invention in an exemplary embodiment, what Idesire to protect by Letters Patent is set forth in the claims whichfollow, it being understood that modifications may be made in theinvention without departing from the spirit of it.

I claim:

1. In a mining machine wherein a plurality of cutter chains are arrangedto engage a plurality of sprockets mounted on a common shaft, andwherein said shaft is adapted to be rotated by said cutter chains, andwherein rotary cutters are adapted to be secured to the ends of saidshaft, said shaft having a center section of a first diameter and endsections of a second diameter which is smaller than the said firstdiameter, splineways in both the center and end sections of said shaft,a plurality of sprockets splined to the center section of said shaft andfixed against rotation relative thereto, a cylindrical member splined toeach of Vsaid end sections, and a sprocket mounted on each of saidcylindrical members, said last named sprockets having cylindrical borescorresponding to the outer surfaces of said cylindrical members, saidlast named sprockets being rotatable relative to said members, wherebysaid last named sprockets are free to iioat on said members and seektheir own alignment relative to the sprockets splined to the centersection of said shaft.

2. The construction claimed in claim l wherein rotary cutting elementsare splined to the outermost end portions of the end section of saidshaft.

3. The construction claimed in claim'2 wherein the center section ofsaid shaft is of uniform diameter throughout the length of said section,and wherein the splineways therein extend continuously throughout thelength of said center section.

4. The construction claimed in claim 2 wherein the center section ofsaid shaft comprises a plurality of splined segments of equal diameterinterconnected by bearing segments of lesser diameter than said splinedsegments.

5. The construction claimed in claim 4 wherein a sprocket is mounted oneach of the splined segments of said center section.

6. In a mining machine wherein a plurality of cutter chains are adaptedto be engaged by sprockets mounted on a common shaft, said shaft havinga center section of a first diameter and end sections of a seconddiameter which is smaller than said first diameter, splineways in thecenter and end sections of said shaft, a plurality of sprockets splinedto the center section of said shaft and xed against rotation relativethereto, additional sprockets mounted on the end sections of said shaft,said additional sprockets each having a circular insert the outersurfaces of which are in sliding contact with the bores of saidsprockets, the inner surfaces of said inserts being grooved to tit thesplineways of said end sections, whereby said additional sprockets mayseek their own alignment relative to said first named sprockets, therebyeliminating the necessity for accurate alignment between the splinewayson said center section and said end sections.

sections of said shaft, said rotary cutting elements being 1 fhft`2,705,626 Bau Apr. 5, 1955 2,92ZS,896 5' t 6 7. The construction claimedin claim 6 wherein rotary 8. The construct-ion claimed in claim 7wherein said cutting elements are splined -to end portions of the endsprockets are al1 of single tooth character. v

adapted to 'be driven by `said shaft upon driving movement ReferencesCited in the me of this Patent of said first named sprockets by thecutter chains attached 5 UNITED STATES PATENTS

